Electrolytic condenser



Nov. 29, 1932. ER Q N v 1,889,416

ELECTROLYTIC CONDENSER Filed Nov. 9, 1929 2 Sheets-Sheet 1 Nov. 29, 1932. R. D. MERSHON 1,889,416

ELECTROLYTIC CONDENSER Filed Nov. 9, 1929 2 Shets-Sheet 2 gnvemto'c $51 M fl t tom FIG.

Patented Nov. 29, 1932 PATENT OFFICE RALPH n. unnsnon, or NEW YORK, N. Y.

EmorRoLY'rIc conimnsnn Application filed November 9, 1929. Serial No. 405,872.

In electrolytic condensers-having a plurality of anodes immersed in an electrolyte and connected in parallel inside the condenser, the ractice heretofore has been to weld the ano es to busbars. It is important that the,

welded joints be perfect since crevices left by imperfect welding may permit lodgment of gas bubbles therein with consequent corrosion of the metal. However, adequate Welding of filming metal, as fpr example aluminum, required considerable skill and care, and the use of a flux is prohibited because of the practical certainty of contamination of the electrolyte by the fluxing agent or agents. Moreover,in a condenser having groups of anodes the anodes of one group are interleaved with thoseof the other. If there are two groups of two anodes each, the anodes of each group may be made by bending a sheet of metal to U-shape, after which the two groups or pairs can be interleaved in the manner suggested'by the symbol conventionally used to represent a condenser in electrical dia grams; but with three or more in a group this method is manifestly impossible.

I have accordingl been led to devise my present invention, w ich has for its chief ob- Ject to provide an assembly of interleaved anodes in which the anodes of each group are integral with each other and in which theassembly is open between the anodes at the side, top and bottom edges thereof to permit free and unimpeded circulation of the electrolyte. Another object is to provide a simple and convenient method of making anode assemblies of the type indicated. To these and other ends the invention com rises the novel features hereinafter describe One form of the invention is illustrated in the accompanying drawings, in which:

Fig. 1 shows a strip of sheet aluminum or other fihning metal shaped and cut\to constitute. a blank for making an anode assembly or cup having four anodes.

' 7 groups as interleaved for use.

Fig. 4 shows a blank such as shown in Fig. 2 s ows in perspective ablank such Fig. 1, provided with stiflening ribs around the edges of the anode sections, and with corrugations inside of the ribs to increase the surface area. 1 FFig. 5 is a cross section on line 55 of ig. 6 is a cross section of an electrolytic condenser having anodes constructed in accordance with my present invention. Any suitable means, not shown,-can be employed to support the anodes and space the same apart, as for example a rack such as de scribed in the prior patent of John S. Riddile and myself, No. 1,285,305, issued November 19, 1918.

In making my improved anode assembly in the preferred way I take a rectangular piece of sheet metal, as 10, Fig. 1, and cut equidistant transverse slits 11 extending from ne of the longer edges, say the lower edge 2, but terminating short of the other edge, and at these ends short slits'13 are cut, extending e uidistantly on either side of the long slits, orming T-shaped slits. I may also cut notches 14 in the lower edge, for the purpose stated below.

The blank described can now be bent at right angles back and forth along the vertical dotted lines at the ends of the T-heads 13, to the form shown in Fig. 2, giving four parallel plates or anodes, 16, 17 18, 19, connected to each other by integral strips 20, 21, 22, at alternate side edges, with such side edges or edge portions extending beyond the strlps. That is, the connecting strips are set in or back from the adjacent side edges.

Two such assemblies can be readily interleaved by inverting one and inserting the other down into it, as illustrated in Fig. 3.

\ In this figure the anodes of the inverted grou are designated 16a, 17a, 18a, 19a. The note es or recesses 14 receive the strips 13, allowing the same to pass the notched plates or anodes without making contact therewith.

In this way the bottom edges of the anodes can be arranged flush with each other in the same horizontal plane, and so also the top edges. If the flush arrangement is not desired the recesses may be omitted, In either case the entire assembly is open at the side, 1

top and bottom edges of the anodes, thus per-. mitting the electrolyte in which the anodes are immersed to circulate freely throughout all parts of the anode assembly. This is a highly advantageous feature as it gives convection currents full play and thereby facilitates dislodgment ofbubbles of gas formed at the surface of the plates. Such bubbles clinging to the plates invariably cause corrosion of the metal and serious injury to the plates results unless the bubbles are removed.

It will of course be understood that the invention is not limited to four anodes, but that as many may be provided as will give the capacity desired.

The anodes may be stiffened by an embossed rib around the edges, as at 23, Figs. 4 and 5. and the connector strip 20 may have a rib 24. To increase the surface area of the plates they may be corrugated, as indicated at 250. The ribs and corrugations can be conveniently formed by die-pressing, as will be readily understood. I

A condenser having anode assemblies of the type described above is illustrated in Fig. 6, having anodes 16. 16a, 17, 17a. 18. 18a, 19, 19a, immersed in an electrolyte 25 contained in a tank or vessel :26. The terminals 27. 28. for connection with an alternating current circuit, may be welded to the appropriate anodes. or they may be integral therewith. as will be readily understood. The, condenser is excited by any suitable source of unidirectional voltage and current, as for example a D. C. generator 29, having its positive pole connected to the midpoint of a choke coil 30 which spans the condenser ter-' minals 27, 28. The negative pole of the exciting source is connected to a non-filming cathode 31 immersed in the electrolyte. By this means the anodes may have impressed upon them a positive potential or bias suflicient to prevent any flow of current from the electrolyte through the films to the metal of the anodes. The anodes may be of the ribbed or corrugated type illustrated in Figs. 4 and 5 but they are not so shown in Fig. 6 to avoid unnecessary complication. For the same reason I do not. show a cover for the tank or a supporting rack for the anodes.

It is to be mulerstood that the invention is not limited to the form'herein specifically thereof, and a'like group with its integral connecting strips at the bottom, the two groups being interleaved by insertion of one into the other.

2. An anode assembly for electroyltic condensers, comprising a group of plates of fihnin g metal arranged side by side and connected at their top edges at alternate side edges by strips of the same metal integral with the plates and set back from the adjacent side edges. the bottom edges of a plurality of the plates being notched to receive the connecting strips of a similar assembly when the two are interleaved in the manner described.

3. An electrolytic condenser comprising an electrolyte and anode groups immersed therein. each group being composed of a plurality of anode plates. the plates being interleaved and those of each group being integrally connected at alternate side edges by strips of the anode metal set back from the adjacent edges. the connecting strips of one group bein g at the top and those of the other being at the bottom.

4. An electrolytic condenser as described in claim 3. in which appropriate anode plates of each group are provided with recesses to receive the connecting strips of the other without making electrical contact. therewith.

5. An electrolytic condenser comprising an electrolyte and groups of anodes immersed therein. each group being composed of at least three anodes arranged side by side. the anodes of each group being connected with each other by integral strips of a single thickness of metal and the groups being interleaved with the anodes of one group alternating with those of another. and the groups being open between the anodes thereof at their top and bottom and both side edges, whereby the electrolyte has unrestricted access to all surfaces of ,the anodes and unimpeded circulation of the electrolyte is permitted through all parts of the assembly.

In testimony whereof I hereto afiix my sig nature.

RALPH D. MERSHON. 

